Two identikit images released by New South Wales police. (NSW police/Newser composite)

In 2005, Australian police set up a task force to look into five sexual assaults in Sydney’s eastern suburbs. They ended up uncovering what could be one of the country’s most prolific serial rapists—and they’re asking the public to help track him down.

Buzzfeed reports a review of those five assaults and a look into other cold cases ballooned the stats: 27 rapes and attempted rapes are now believed to have been committed by one man.

The cases are linked by DNA evidence and similarities in their circumstances; victims were threatened with a knife (in some cases he showed it, in others not), and some of the locations were similar: Centennial Park and near the Bondi to Bronte coastal walkway.

But no matches were found in running the DNA against Australia’s database or international records, reports AAP. Police say the “blitz attack” rapes, which “were committed very, very quickly with very little warning to the victim,” occurred between 1985 and 2001; news.com.au reports his victims ranged from ages 14 to 55.